Trammel-point for beam-compasses



NiTnD STATES PATENT Ormcn.

WILLIAM J. HOUCK AND ARLINGTON W. HOUOK, OF NEVARK, NEW JERSEY.

-TRAMMEL-POINT FOR BEAM-COMPASSES.

SPEGIFICATION forming part of Letters Patent No, 510,139,,dated December5, 1893.

Application iiled June 19,1893. Serial No. 478,068. (No model.)

To all whom it may concern.-

Beit known that we, WILLIAM J. HoUcK and ARLINGTON W. HoUcK, citizens'ofthe United States, residing at Newark, inthe county of Essex and Stateof New Jersey, have invented an Improvement in Trammel-Points, of whichthe following is a specification.

Architects, builders, carpenters, and others, frequently employ a bar orstrip of wood to which are connected points to be used in measuring orin describing circles or arcs of circles, and sometimes the points areboth made of metal and sometimes one point is provided with a pencil.Difficulty has heretofore been experienced in constructing the pointsinsuch a manner as to be adapted to bars that are suficiently heavy fortrammels of consider-v able length or sufficiently light for shortlengths, and in addition to this the clamping devices that haveconnected the points with the bars are very liable to injure the surfaceof the wood of the bar, and this is objectionable not only in the matterof appearance but also the depressions resulting from the pressure ofthe clamping screws are liable to interfere with the easy and accurateadjustment of the points upon such bar.

In the present invention We make use of two similar clamps to act atopposite edges of the trammel or beam and a rod or bar passes throughthese clamps and at one side of the beam and terminates with a screw andnut, and the other end of the rod is formed asv a point. By this meansthe clamps act directly upon the rod forming the point and also upon theedges of the bar or beam to clamp the same, and the extent of surface issufiicient to prevent injury to the wood of the beam or bar, and theclamping` devices are adapted to bars that are either light or heavyaccording to their length; and in cases where a pencil is required, atube or socket for the reception of the same is provided adjacent to thetrammel point and preferably upon one of the clamps.

In the drawings, Figure 1 is an elevation of the trammel point and aportion of the bar. Fig. 2 is a view of the trammel point sectionallylofthe bar.k Fig. 3 is a plan view endwise of the point.

The point of the rod A is preferably of steel sharpened at the end 2 andscrew threaded at the other end for the reception of the nut 3, and thisrod A passes through the clamps B and C and it is secured to the clamp Oby any suitable means, such for instance as a cross pin 4, and-thesurfaces 5 and 6 are adapted to rest upon and grasp the opposite edgesof the trammel or beam D which may be of any desired length and ofsectional shape adapted to the surfaces 5 and 6 oftheclamps B and C.

If desired the surfaces 5 and 6 may be at a slight inclination as shownby dotted lines in Fig.- 2 so that the trammel'or beam D may betriangular or trapezoidalin section and hence may be of any desiredWidth to obtainr the re quired strength; we have however represented theclaws 7 upon the back edges of the clamps B and C, which claws pass downeither behind the back surface of the trammel or beam D or into groovesin the opposite surface of such trammel or beam, as indicated by. thedotted lines at 8. By this construction the trammel points are adaptedto the trammel or bar which may be made use of, and the nut 3 acting topress the clamps toward each other, causes their surfaces 5 and 6 tograsp and firmly bind upon the opposite edges of the trammel or beam D,and the extentof surface contact is sufficient to prevent the Woodv ofthe trammel being dented or injured by the compressing action of thenut; hence these improved trammel points are adapted to bars or trammelsof ornamental wood with highly finished surfaces without the risk ofinjury.

At E we have represented a tube connected with the clamp O and adaptedto receive a pencil passing through the same, as indicated by the dottedlines.

It is to be understood that with a beam compass two of the trammelpoints, as before described, are made use of and that both may beadapted to the receptionof pencils, or only one, or in cases wherepencils are not required the tube E may be dispensed with.

We claim as our inventionl. The combination with the rod A pointed atone end and screw threaded at or near the other end, of the clamps B andC through which the rod A passes and which clamps have surfaces 5 and 6adapted to engage and clamp IOO upon the opposite faces of the trammelor. bar, and the nut 3 for acting upon the movable clamp, substantiallyas set forth.

2. The combination with the trammel or beam, of a rod adapted to passacross at one side of the same, two clamps upon said `rod one of whichis permanently connected, and a uut screwed upon the rod to act upon theother clamp, such clamps having surfaces adapted to grasp the trammel orbeam at the opposite edges thereof, substantially as set forth.

3. The combination with the trammel or beam, of a rod adapted to passacross at one side of the same, two clamps upon such rod one of which ispermanently connected, a nut 15 down at the back of the trammel near thezo edges thereof, substantially as set forth.

Signed by us this 14th day of June, 1893.

WVM. J. HOUCK. ARLINGTON W. HOUOK.

Witnesses:

JOHN J. TOWER, WILLIAM I-I. COLE.

